Case Study 92: Core Sampling in UXO Contaminated Waterways


Real-time metal detection eliminates need for pre-coring survey.

Client Needs: The client needed vibracore samples in an area known to contain UXO (unexploded ordnance). They were concerned about our electro-vibracore making contact with UXO.

An EM survey could have been performed to provide markout pre-coring, however this approach has several drawbacks:

• Increased time on the water for surveying and in the office for for post-processing the EM data; both leading to increased cost.

• Variability in GPS accuracy during survey and later vessel positioning error can lead to small variations in location.

• Traditional EM survey becomes less sensitive with sediment depth. A 20mm round may be easily detectable at 3ft but not necessarily 20ft.

Solution: Our patent in process EM Smartcore solves these problems. Utilizing a metal detecting EM nose cone at the end of a core barrel, the Smartcore essentially performs real-time markout during the coring process.

The EM Smartcore approach provides several key benefits:

• Eliminates days surveying on the water and associated office time processing data.

• Elimination of GPS Error – no room for error with variability of GPS during survey and reacquisition, removing all uncertainty of GPS error from markout survey and and reacquisition during coring activities.

• Deeper detection – a traditional EM survey has a limited detection depth. Since the Smartcore’s EM coil is on the tip of the core barrel, it will have an equally effective detection depth at a 20ft penetration as it would at a 1ft penetration.

Depending on depth needed Aqua Survey can perform 6-20 Smartcores a day.

Results: Utilizing our Smartcore services, our client saved time and money by eliminating the need for a pre-coring markout survey. Additionally, the Smartcore ensured greater safety by providing increased detection depth and eliminating any potential GPS inconsistencies.

What If: What if it wasn’t UXO but a utility the client was concerned about making contact with?


What If Solution:
The Smartcore provides all of the same benefits to avoiding contact with utilities as it does UXO. Additionally, because utility surveys are typically performed with a magnetometer, which only detects ferrous metals, the Smartcore’s EM nose cone provides an added benefit in that it detects both ferrous and non-ferrous

Want to know more?

Smartcoring eliminates the need to perform geophysical field surveys, subsequent data processing and charting prior to getting on the water to sample.

It’s also a sure way to greatly reduce the probability of coring equipment making contact with utilities, UXO or other metal objects. Our Smartcore technology allows our field teams to vibracore in areas known or suspected of having utility runs or UXO while maximizing the possibility of collecting cores safely and not making contact with metal objects.

If you’d like to learn more, reach out to hayes@aquasurvey.com with any questions.